Steam Spy isn’t dead, but it isn’t as accurate as it was, creator says

The developer who created Steam Spy — the tool that has tracked game ownership on the PC gaming marketplace for the past three years — says the site is currently “not very accurate, to be honest” following changes to Steam’s API. But he is not giving up on charting Steam games’ sales, popularity and player base.

In a blog post today, Sergey Galyonkin said he’s using some machine learning methods he developed in a past academic pursuit to measure sales. In one case, his algorithm came close to the self-declared sales of the city-builder Frostpunk (which launched on April 24).

Bigger picture, though, “many features of the site” are still unavailable, even if Galyonkin says they may be coming back soon. “The basic features (the number of owners, playtime distribution, related games) are working fine already,” he wrote.

On April 11, Valve announced changes that pulled a user’s owned games from the information shared to the Steam API unless that owner actively opted-in. This was vital information to Steam Spy, which launched in 2015. Galyonkin said he does not think the recent changes to Steam’s user information policy came because of the General Data Protection Regulation (GDPR), which is a European Union law passed in 2016 that becomes enforceable in May of this year.

“Valve still exposes your real name, achievements, groups, screenshots, and friends by default and still hasn’t updated their EULA to comply with GDPR,” he wrote. “It doesn’t mean they won’t, but the API change was definitely not caused by that.”

Steam Spy’s old algorithm worked with the user information supplied by that API, and then another change to the Steam Store’s API ended up “making it useless.” Galyonkin reached out to Valve with a proposal to continue running his algorithm without exposing, or being exposed to, any user’s personal data.

Galyonkin said Valve Corp. — in the characteristically opaque way it often deals with the public — only acknowledged that it received his message but did not respond to the substance of his request.

Galyonkin then went back to some work he had done about 15 years ago on an unfinished Ph.D. thesis for predicting economic outcomes. Using “a ton of coincidental data on games,” most of which isn’t provided by Steam, he saw some good results. Galyonkin says that his newest analysis can get within a 10 percent margin of error for 90 percent of 70 games.

“I’m still not entirely happy with my new algorithm and its precision,” he added. “I do believe in giving everyone the access to the essential information, but until I fix everything, Steam Spy will be semi-closed to the general audience.”

Regardless, he will continue his work, while acknowledging that “it’s still possible that Valve will make another move to shut down the service.” Until that happens, any report of Steam Spy’s total death is premature.